The invention provides an LEACH protocol improvement method capable of lowering energy consumption. A basic system comprises normal nodes, cluster header nodes, forwarding nodes and a base station. The specific cycle operation steps comprise network topology determination, initialization, selection of the cluster header nodes, cluster forming, data transmission, selection of the cluster header nodes and cluster forming. According to the defects of an LEACH protocol, improvement is conducted from the aspects of selection of cluster heads, cluster forming and a data transmission mode. In selection of the cluster heads, the comprehensive influences of the energy of the nodes, the distance to the base station and density are considered, the burdens of the cluster heads are balanced, and distribution and energy consumption of the selected cluster header nodes are made balanced in a network. In cluster forming, the mode of grid clustering is used, the nodes calculate the two-dimensional values of grids where the nodes are placed by themselves, and the effectiveness of node energy is guaranteed. In data transmission mode, a routing mode with single-hop and multi-hop combined is used according to the distance of the cluster header nodes and the base station, the energy consumption of network nodes is lowered by the purpose that the energy utilization rate is highest.